1. Field of the Invention
The present invention relates to a device for maintaining a specimen securely mounted over a viewing window and, more particularly, to apparatus for rapidly and accurately mounting a film specimen flat over a viewing window without mechanical contact.
Applications exist where it is important to mount, position and observe a film specimen for analysis over a viewing window in such a way (1) that there is no mechanical contact applied from the top of the specimen to hold it against the viewing window, (2) that the specimen is held flat against the viewing window, and (3) that the thickness of the apparatus or device for maintaining the specimen in place not exceed approximately 0.07 inch (1.75 mm). It is essential in such apparatus that the film specimen be held firmly in place for observation with a microscope or other means, that the apparatus employed to hold the specimen in place not obstruct the viewing area of interest and that the apparatus employed to hold the specimen in place prevent any deformation of the specimen in the area of viewing interest.
Vacuum means for maintaining specimens in place have been known for years, but prior to the present invention no known system had the capability of achieving the desiderata mentioned above in which a film specimen could be quickly, easily, firmly and accurately mounted.
2. Description of the Prior Art
Holding objects in place with a vacuum has been done for many years. U.S. Pat. No. 3,723,006 discloses apparatus which can be used for holding particulate specimens, but the disclosed apparatus is not capable of mounting film specimens for inspection or analysis over a viewing window.
U.S. Pat. Nos. 3,029,695 and 3,031,924 are directed to microscope slides having sealed specimen chambers interiorly thereof. The sealed specimen chamber can be partially evacuated. The purpose of the vacuum, however, is not to retain the specimen in place. Moreover, such specimen chambers do not provide easy, quick, convenient mounting of specimens; do not insure that the specimen will be maintained flat against the viewing area; and do not prevent the specimen from being distorted and/or contaminated by the means employed to mount and retain the specimen in the microscope slide.